Fuel feed and charge forming apparatus



y 23, 1967 B. c. PHILLIPS 3,321,192

FUEL FEED AND CHARGE FORMING APPARATUS Filed May 5, 1965 3Sheets-Sheet 1 INVENTOR. 55/21/490 6. pH/LL/PS Array/w y y 3, 19%? B. c. wuniwsps 3,321,192

FUEL FEED AND CHARGE FORMING APPARATUS Filed May (5, 1965 5 $heets-Sheet 6 66 206 (94 (9K ma WW 56- QI J; 6? l y 23, 1967 B. c. PHILLIPS 3,321,192

FUEL FEED AND CHARGE FORMING APPARATUS Filed May 5, 1965 3 Sheets-Sheet 5 Arrow/5y United States Patent 3,321,192 FUEL FEED AND CHARGE FORMING APPARATUS Bernard C. Phillips, Toledo, Ohio, assignor to The Tillotson Manufacturing Company, Toledo, Ohio, a corporation of Ohio Filed May 3, 1965, Ser. No. 452,830 3 Claims. (Cl. 261-35) This invention relates :to a fuel feed system and apparatus for delivering a fuel and air mixture to an internal combustion engine and more especially to an apparatus of a combined charge forming apparatus and a variable volume pulse operated fuel pumping means embodied in a chamber in the charge forming apparatus,

In the operation of internal combustion engines, particularly those of :the two cycle type used for powering chain saws, lawn mowers, outboard marine engines and the like, it is imperative to provide for the delivery of fuel and air mixture irrespective of the relative position of the engine. Fuel feed and charge forming apparatus for use with chain saw engines must be adaptable for operation in extreme angular or inverted positions without interruption or impairment of the delivery of combustible mixture to the engine.

Diaphragm type fuel pumps, that is, a type of pump wherein a planar diaphragm is vibrated by pulse pressures from an engine crankcase have been extensively used for delivering fuel to a charge forming apparatus or carburetor embodying a metering diaphragm actuated by aspiration or reduced pressure in the mixing passage for controlling the flow of fuel into a fuel chamber of the carburetor for delivery into the mixing passage.

In constructions of this character, the pumping diaphragm and the fuel inlet control or metering diaphragm have been arranged in stacked parallel relation at one side of the mixing passage and in some types of construction the pumping diaphragm is disposed at one side of the mixing passage and the fuel inlet control diaphragm disposed at a diametrically opposite side of the mixing passage. While the planar type of pumping diaphragm has been used extensively, the diaphragm must :be vibrated in directions normal to the plane thereof, which vibrations stretch or imparts stresses to the diaphragm which consume substantial energy of the pulse pressures in the operation of the pumping diaphragm. In the use of planar type pumping diaphragms, connecting channels of some length are provided between the pumping chamher and the source of variable pressures and the inertia of the air in these connecting channels impair the pump ing efliciency, especially, where the pumping pulses occur at frequencies of 8000 or more times per minute as when the pump is employed with a high speed two cycle engine.

The present invention embraces a system and arrangement for feeding liquid fuel to a charge forming apparatus through the utilization of a yieldaJ-ble pulse-responsive tubular component or envelope disposed in a cavity in the body of the charge forming apparatus and arranged to be influenced by a source of varying fluid pressure and which is associated with an element having flap valves for effecting fuel flow by the varying volume of the pulse responsive component.

An object of the invention embraces a charge forming apparatus of the diaphragm type having a body member having a mixing passage and a cavity accommodating a tubular thin-walled element or component of yieldable material adapted for direct connection with a source of varying fluid pressure for pumping fuel in association with a flexible flap valve construction disposed at a marginal region of the diaphragm of the charge forming apparatus for controlling fuel flow through inlet and outlet ports to effect delivery of liquid fuel from a supply to the charge forming apparatus under the influence of the varying volume of the component or element through its actuation by varying fluid presures.

Another object of the invention resides in a charge forming apparatus embodying a variable volume fuel pumping component, the charge forming apparatus incorporating a metering diaphragm for controlling the fuel flow into a fuel chamber, the diaphragm having a marginal region provided with integral flap valves controlling inlet and outlet ports for feding fuel to the charge forming apparatus by the varying volume of the fuel pumping component by varying fluid pressures acting on the variable volume component.

Another object of the invention resides in a charge forming apparatus embodying a pulse operated tubular element envelope or sac-like means in association with valve means for eifecting fuel flow from a supply to the charge forming apparatus under the influence of varying volume of the pulse responsive element, the element being of a cross-sectional configuration and fashioned of thin yieldable material offering a minimum resistance to flexure by pressure pulsations to promote delivery of liquid fuel to the charge forming apparatus under all condition of an engine with which the charge forming apparatus may be used. Still another object of the invention resides in a carburetor embodying a planar type of fuel flow regulating or metering diaphragm actuated or controlled by aspiration in the mixing passage in conjunction with a fuel feed element embodied in the carburetor in association with flap valves of yieldable material disposed adjacent a marginal region of the diaphragm cooperating with inlet and outlet ports providing a compact arrangement wherein the fuel flow channels are of comparatively short lengths promoting improved fuel pumping efliciency at all engine speeds.

Another object of the invention resides in a charge forming apparatus embodying a planar type of diaphragm for regulating fuel flow into a fuel chamber wherein the body of the charge forming apparatus is fashioned with a cavity accommodating an elongated thin-walled component of yieldable material having a single opening for communication with a source of varying fluid pressure and wherein the cavity is associated with flap valve means for inlet and outlet ports arranged to convey fuel from a supply to a fuel chamber in the charge forming apparatus under the influence of pressure pulsations set up by varying fluid pressures.

Another object of the invention resides in the provi sion of a fluid pumping component of thin-walled flexible material of a cross-sectional configuration enhancing flexing or distortion under fluid pressure Without appreciable stretching of the yieldable material whereby the pumping component responds to pressure pulsations with a minimum of resistance thereby attaining improved pumping efliciency.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE 1 is a top plan view of one form of fuel feeding and charge forming apparatus of the invention;

FIGURE 2 is a view of the mounting end of the charge forming apparatus showing the variable volume fuel pumping component in a cavity of the charge forming apparatus;

FIGURE 3 is a longitudinal sectional view taken.sub-.

stantially on the line 3--3 of FIGURE 1;

FIGURE 4 is a bottom plan view of the apparatus shown in FIGURE 1 with portions broken away for purposes of illustration;

FIGURE 5 is a detail sectional view taken substantially on the line 5--5 of FIGURE 4;

FIGURE -6 is an enlarged isometric view illustrating a form of pumping component of the invention; 4

FIGURE 7 -is a plan view of a planar type diaphragm for controlling fuel flow into the fuel chamber of the charge forming apparatus, the diaphragm embodying flap valves for cooperation with fuel ports;

FIGURE 8 is a sectional view taken substantially on the line 88 of FIGURE 1; i

FIGURE 9 is a sectional view taken substantially on the line 9-9 of FIGURE 2;.

FIGURE 10 is a fragmentary detail sectional view taken substantially on the line 1010 of FIGURE 4;

FIGURE 11 is v a fragmentary detail sectional view taken substantially on the. line 1111 of FIGURE 4-,

FIGURE 12 is a bottom plan view with portions broken away illustrating flap valves in a member disposed at the marginal region of a fuel metering diaphragm;

FIGURE 13 is a plan view of a sealing gasket embodying integral flap valves; 1

FIGURE. 14 is a plan view of a fuel flow control diaphragm usable with the gasket shown in FIGURE 11;

FIGURE 15 is anend view of a carburetor illustrating r a modified arrangement of the fuel pumping component; FIGURE 16 is a sectional view similar to FIGURE 5 illustrating the pump component arrangement of FIG- URE 15, and

stantially on the line 1717 of FIGURE 15.

The combined fuelfeed and charge forming arrange ment of the invention is particularly usable with engines of the two cycle type such as those employed for powering chain saws, lawn mowers and the like, but it is to be understood'that the invention maybe employed with other engines providing varyingfluid pressures suitable for actuating a fuel feed component.

, Referring to the drawing in detail and particularly the 7 form of the invention illustrated in FIGURES 1 through -11, the construction includes a charge forming apparatus or carburetor of the type wherein a planar diaphragm controls fuel flow to the carburetor under the influence of engine aspiration "in themixing passage of the car- .buretor. The fuel 'feed and charge forming apparatus includes a body-or body member 10 formed with a mixing passage 12 in which is disposed at Venturi 14 having a choke band or restricted region 16. v ,The body 10 is provided with an air inlet region 18 and a mixture outlet region20.

The .outlet end of the body 10 is fashioned with a mounting flange 22 which, asshown in FIGURE 1, is adapted to .mate with a flange 24.formed on an engine crankcase by threaded studs 26 receiving securing nuts 28. The air inlet end of the carburetor body may be equipped withfan air filter (not shown) of. conventional. construction.. .The air inlet portion of the body-is provided with bosses 30 bored to-receive a'shaft 31 equipped with a choke valve '32v and. an arm 34 for manipulating the choke valve.

T he-body 10 is-formed with bosses 36 bored to accommodate a shaft 38 supporting adisc-like throttle-valve 40 for controlling the flow of fuel and air mixture to the crankcase offa two cycle engine, and is secured to the engaged with .a pin 46 for normally biasing the throttle valve 40 toward engine idling position.

The body 10 is provided with a boss 48 accommodating an adjusting screw 49 threaded in an opening in the boss 48, a coil spring 50 surrounding the adjusting screw 49 for frictionally retaining the adjusting screw 49 in adjusted position.

The screw is adapted to be engaged by the manipulating arm 42'to limit the movement of the throttle toward closed position. By adjusting the screw 49, a near closed position of the throttle 40 may be regulated for engine idling purposes. p p

The body 10 is formed with a substantially circular recess providing a shallow fuel compartment 54. A flexible membrane or diaphragm 56 extends across the recess and forms a flexible wall of the fuel compartment 54, as shown in FIGURES 3 and 8. A generally annularlyshaped gasket 58 is disposed between the diaphragm 56 and an annular bos portion 60 formed on the body 10 and defining the perimeter of the shallow fuel compartment 54. A second member or plate 62 is disposed beneath the diaphragm 56 and is fashioned with a shallow air chamber or recess 64 to accommodate flexing movements of the diaphragm 56. j

The air ordry chamber 64 beneath the diaphragm is vented to the atmosphere through a vent 66, shown in FIGURE 3. A plurality'of screws 68 extend through registering openings in the peripheral region of the member 62, the diaphragm 56 and the gasket 58, the screws being threaded into openings formed in the body 10 to thereby secure thesecornponents in assembled relation. The diaphragm '56 is made of highly flexible thin I v material such as a fine mesh fabric coated with synthetic FIGURE 17 is a fragmentary sectional view taken subrubber or resin to render the diaphragm impervious, or the diaphragm may be fashioned of resinous material having similar characteristics.

Disposed within a recess 72 forming a part of the fuel compartment 54 is a lever 74 fulcrumed intermediate its ends upon a pin 75 carried by the body 10. The long arm of the lever is adapted to be engaged by a headed member or rivet 76 mounted at the central region of the diaphragm, the rivet extending through reinforcing discs 77 and 78 disposed at opopsite sides of the diaphragm and secured to the diaphragm by the rivet.

The short arm of the lever 74 is adapted for engagement with an end of a fuel inlet control valve body 82 of elongated shape slidably disposed within a valve cage or guide 84, the latter being threaded into a bore in the body 10. Disposed above the valve guide 84 is an annular valve seat 86 of yieldable material, such as synthetic rubber, the valve member 82 having a conicallyshaped valve portion 88 for cooperation with the fuel inlet port in the valve seat 86. The valve body 82 is of polygonal cross section, such as a square or triangle, to facilitate fuel flow past the valve member 82 into the fuel compartment or chamber 54.

An expensive coil spring 90 engages the long arm of the lever at a region close to its fulcrum for biasing the lever in a direction to close the fuel inlet valve 88. The carburetor body is fashioned with a main orifice 92 opening into the restricted region 16 of the Venturi 14 for delivering fuel from the fuel compartment 54 into the 92 receives its fuel from the fuel compartment 54 through a duct 100, a fuel passage 102 and a restricted passage 104. An adjustable valve member 106 is threadedly mounted in a bore in the body 10 and is provided with a needle valve portion 108 cooperating with the restric tion 104 to meter or regulate the delivery of fuel to the main orifice 92. The valve body 106 is provided with a knurled head 107 to facilitate the needle valve.

The fuel conveying passages and fuel metering means for the secondary orifices are illustrated in FIGURE 11. The supplemental chamber 98 is in communication with the fuel compartment 54 by a restricted passage 110, bore 112 and a duct 114. A valve body 116 is threaded into a bore in alignment with the bore 112 and is provided with a needle-shaped valve portion 118 cooperating with the restricted passage 110 to meter or regulate flow of fuel from the compartment 54 to the idling and low speed orifices 94 and 96. The valve body 116 is pro vided with a knurled head 117 for manually adjusting the needle valve 118.

The needle valve 108, for metering fuel flow to the main orifice 92, cooperates with the restriction 1114 in a manner whereby the liquid fuel at this region forms a capillary seal or liquid block to prevent back bleeding of air through the main orifice 92 into the secondary fuel delivery system when the latter system is delivering fuel into the mixing passage.

A carburetor embodying this construction providing a capillary seal is disclosed in my Patent 2,841,372. It is to be understood that other valve means may be employed'in association with the main orifice or main fuel delivery means to prevent back bleeding of air through the main orifice.

The arrangement of the invention is inclusive of a pumping component comprising a pressure responsive tubular element having a closed end and of flexible or yieldable material providing a variable volume chamber. The tubular element is disposed in a chamber provided in the carburetor body. Inlet and outlet valves are provided for one of the chambers for effecting pumping of liquid fuel, the other chamber being connected with a source of varying fluid pressures to effect pumping action of the tubular element. As shown in FIGURES 2, 3, 5, 6 and 9, a region of the carburetor body 10 adjacent the mounting flange 22 is formed with an elongated bore or chamber 122 which receives a tubular or sac-like pumping element or component 124 shown, per se, in FIGURE 6.

The pumping element 124 is formed of flexible or yieldable impervious material and is fashioned with an elongated body 126, one end being closed by an integral end wall portion 128, as shown in FIGURE 9, the open end having an enlarged laterally extending circular flange or head portion 130, the latter fitting in a counterbore 132 formed in the mounting flange 22, as shown in FIG- URE 3. The pumping element 124 is fashioned of synthetic rubber or flexible resinous plastic or other material which is resistant to deterioration by hydrocarbon fuels.

The cross sectional configuration of the tubular .pumping element 124 is shown particularly in FIGURES 2 and 5 and is preferably star-shaped formed by lengthwise arranged flutes 134. This configuration provides a chamher 136 which is of cross-like or star shaped in cross section. The entrance to the pulsing chamber 136 being at the planar face of the mounting flange 22 abuts a gasket 23 at the face of the boss portion 24 of the engine crankcase 25, and is in registration with a passage 27 in the boss 24 and a passage in the gasket 23 whereby the chamber 136 of the pumping element 124 is in direct communication with the interior of the engine crankcase.

Through this arrangement the varying fluid or air pressures in the crankcase of the engine, during engine operation, are effective in the chamber 136 to flex or distort the wall regions defined by the flutes 134 to provide a pumping action due to the rapid pressure variations in the engine crankcase. A conventional reed valve construction (not shown) is disposed at the passage in the crankcase of the two cycle engine in registration with the mixture outlet of the carburetor.

The cross-sectional star-shaped configuration of the pumping element 124 has numerous advantages as commanual adjustment of pared with a circular cylindrically-shaped pumping element.

While the material of the pumping element is flexible and yieldable and may be of stretchable character, the fluted construction enables radial distortion or radial movement of the material defining the flutes 134 under the influence of pumping or pressure pulses without appreciable stretching of the material. Thus, the fluted configuration provides for a flexing action of the pumping element providing a variable volume pumping chamber without the expenditure of energy in stretching the element.

Thus, distortion or flexing movements of the fluted regions occurs at high frequencies without stretching the material providing a highly eflicient pumping action with a maximum movement of the material of the flutes with a minimum expenditure of energy. The flexure of the walls of the pumping pulsing element 124 continuously varies the effective volume of the chamber 122 enclosing the pumping element 124, providing a variable volume fuel chamber.

Valve means is provided for controlling fuel flow from a supply to the fuel chamber 122 and for controlling flow of fuel from the chamber 122 to the region of the inlet valve 88 of the carburetor, shown in FIGURE 8. In the form of construction shown in FIGURES 1 through 11, the valve means comprises flexible flap valve portions integrally formed on the fuel metering diaphragm 56. As particularly shown in FIGURE 3, the member or plate 62 is provided with a circular ridge providing a seat for a gasket 142.

Seated against the gasket 142 is a cap member or closure 144 of convex shape, the closure 144 being secured to member 62 by a screw 145 extending through an opening in the member 144 and threaded into a bore formed in a central boss portion 148 on the member 62. The member 144 is provided with a tubular nipple 151i adapted to receive the end of a flexible tube 152 connected with a fuel tank or other fuel supply, the passage 153 in the nipple admitting fuel into a recess 154 provided by the closure 144. The member 62 is fashioned with an annular shaped fuel receiving recess 156, a screen or filter 158 for filtering the fuel being disposed between the recess 154 and the annular recess 156, the screen being held in place by the gasket 14 2.

The :member 62 is fashioned with a first fuel port 160 which terminates adjacent a flexible flap valve member 162 formed as an integral part or component of the diaphragm 56, as shown in FIGURE 4. The adjacent portion of the carburetor body 10 is fashioned with a space 164 to accommodate opening movements of the valve flap 162. The valve flap 162 is adapted for hinging action about a region 163 of its integral connection with the diaphragm 56. The space 164 is connected by a passage 166 with the chamber 122 exteriorly of the flexible pumping element 124, as shown in FIGURE 5.

The passage 166 is in communication with a passage 168 formed in the member 62 which is in communication with an outlet port 170. Disposed above the outlet port 170 is a second or outlet flap valve 172 also formed integrally with the diaphragm 56 for hinging movement about a region 173, the relative positions of the flap valve being shown in FIGURES 4 and 5. The body 10 is fashioned with a space 174 to accommodate opening movements of the outlet flap valve 172. The space 174 is in communication with a fuel conveying passage 176 in the member 62 which is in communication with a fuel .pas sage 173 formed in the body 10, as shown in FIGURES 5 and 8.

The passage 178 is connected by a duct 180 to the inlet region adjacent the fuel inlet valve 88 for delivery into the fuel compartment 54 when reduced pressure in the mixing passage 12 influences or flexes the diaphragm 56 to open the fuel inlet control valve 88. Thus, in this form of the invention, the inlet and outlet flap valves 162 and 172 for the variable volume fuel chamber 122 are integrally formed with the planar metering diaphragm 56 at a side or marginal region of the diaphragm, as shown in FIGURE 4.

The operation of the fuel pumping arrangement and flow paths of the fuel are as follows: The fuel supply tube 152 is connected with a fuel supply tank (not shown) and, under the influence of the pumping means 124, fuel flows through the nipple passage 153, chamber 154, through the filter 158 to the fuel inlet port 160.

The open end of the flexible pumping member or component 124 is in communication with the engine crankcase through the passage 27, shown in FIGURE 9, and is adapted to be flexed by the varying fluid pressures in the crankcase of the two cycle engine, the varying pressures being set up by reciprocation of the engine piston.

At each revolution of the engine, a pressure pulse and a negative pressure are established in the crankcase which pressures are communicated to the interior of the flexible pumping member 126. The pressure variations alternately enlarge and contract the volume of the interior chamber 136 of the member 126 by flexing the corrugated or fluted regions 126 without appreciable stretching of the material of the pumping element. The expanding and contracting volume of the interior 136 of the member 126 causes a reciprocal contraction and expansion of the effective volumes of the fuel chamber 122 surrounding the member 126.

Thus the effective volumetric content of the chamber 122 is alternately enlarged and contracted through the radial flexing movements of the flutes 126 of the pumping element. When a negative pressure in the engine crankcase contracts the interior 126 of the pumping member, the effective volume of chamber 122 is enlarged and the flap valve 162 is opened by the reduced pressure in the fuel chamber 122 to admit fuel from the supply through the port 160 into the space 1164 and passage 166.

Upon a pressure pulse impressed in the interior 136 of the pumping member from the engine crankcase, the effective volume of the fuel chamber 122 is contracted, exerting or establishing pressure on the fuel in the passages 166, 168 and the outlet port 170.

This pressure opens the outlet flap valve 172 causing fuel under pressure to flow through the connecting passages =176, 178 and 180 to the region of the inlet valve 88 in the carburetor, shown in FIGURE 8. The operation of the engine sets up reduced pressure in the mixing passage, and air and fuel mixture moving into the crankcase of the engine establishes reduced pressure or aspiration in the fuel chamber or compartment 54 in the carburetor.

The reduced pressure in the fuel compartment '54 raises or flexes the diaphragm 56 upwardly or in a direction to swing the lever 74 in a counterclockwise direction, as viewed in FIGURE 8, whereby the inlet valve 88 opens to admit fuel from the pumping means into the fuel chamber 54 for delivery into the mixing passage, either through the main orifice 92 or one or both of the sec ondary orifices 94 and 96, depending upon the position of the throttle valve 40 and the speed of the engine.

The pumping member 124 is actuated by each pressure pulse from the engine crankcase and hence if the engine is operating at six thousand revolutions per minute the member 124 of pressure pulses per minute, providing an effective pumping means through the provision of the flexible element 124 shaped to effect pumping action with no appreciable stretching of the material of the pumping memher.

This arrangement provides an etficient pumping means because energy of the pressure pulse is not required to stretch the material but only in flexing the material to attain a pumping action.

The arrangement is compact in that the inlet and outlet valves 162 and 172 are fashioned as integral comis being acted upon by the same number p ponents of the fuel metering diaphragm 56 of the carburetor thus eliminating the use of a diaphragm type pumping element of the character shown in my Patent 2,796,838. The fuel supplied to the main orifice 92 is regulated by manual adjustment of the needle valve 108, particularly shown in FIGURE 10.

The needle valve 108 cooperates with the restricted passage 104 whereby fuel at this region provides a capillary seal to prevent air bleeding back through the main orifice 92 from the mixing passage into the secondary fuel delivery system when the latter is delivering fuel into the mixing passage through one or both of the secondary orifices 94 and 96. The principle of the capillary seal construction is described and claimed in my Patent 2,841,372. The needle valve 118, shown particularly in FIGURE 11, is manually adjustable for regulating or metering fuel delivery from the fuel chamber 54 to the engine idling and low speed orifices 94 and 96.

FIGURE 12 illustrates a modification of flap valve arrangement for controlling flow of liquid fuel through inlet and outlet ports and shown in FIGURE 5 and hereinbefore described. In the arrangement shown in FIGURE 12, the carburetor body 10' and member 62, the orifice and fuel duct arrangement, are the same as hereinbefore described in the construction shown in FIG- URES 1 through 6, 8 and 9.

In the arrangement shown in FIGURE 12, the metering diaphragm is of the same character as the diaphragm 56 but is of a lesser dimension at the region of the fuel inlet and outlet ports, the periphery of this region of the diaphragm being defined by the edge 192 shaped as shown in FIGURE 12. In this form of the invention, the flap valves 162 and 172 are formed as integral components of a membrane or fiat member 196 which may be of the same flexible material as the material of the diaphragm 190. The exterior edge contour 198 of the membrane or member 196 is of the same contour as the corresponding edge region of the metering diaphragm, shown in FIGURE 4.

The inner edge region 200 of the membrane 196 is of a shape reciprocal to the contour 192 so that the adjacent edges of the metering diaphragm 190 and the membrane 196 are contiguous without overlapping, as shown in FIGURE 12. The member 62 is of the same shape as the member 62 and the bolts 68 extending through member 62 serve to clamp or retain the membrane 196 in its operative position, shown in FIGURE 12.

In this form, the body 10' is provided with dowel pins 202 which extend through openings in the membrane 196 to properly locate the membrane 196 with respect to the metering diaphragm 190. The operation of the form of the invention shown in FIGURE 12 is substantially the same as that shown in the form of the invention hereinbefore described and the flap valves 162 and I172 function in the samemanner to control the inlet and outlet ports as in the form shown in FIGURE 4 where the flap valves are an integral part of the metering diaphragm 56.

FIGURES l3 and 14 illustrate an arrangement of a member and metering diaphragm wherein the flap valve means are integral components of an annular gasket member which is contiguous with the peripheral region of the metering diaphragm. FIGURE 14 illustrates a metering diaphragm 206 of the same configuration or shape as the diaphragm 56 shown in FIGURES 3 and 4. A region of the diaphragm 206 extending laterally beyond the fuel chamber is provided with openings 208 and 210. Disposed beneath the diaphragm 206 is an annular gasket 212 of substantially the same shape as the diaphragm 206.

The regions of the gasket 212 contiguous with the openings 208 and 210 are formed with flap valves 162 and 172" fashioned of the material of the gasket and integral therewith. The openings 208 and 210 in the metering diaphragm 206 accommodate movement of the flap valves in the gasket 212. The flap valves i162" and 9 172" control fuel flow through inlet and outlet ports 160 and I170, shown in FIGURE .5.

The gasket 212 is provided with openings 214 to accommodate dowels 202, shown in FIGURE 12 to position the gasket 212 in proper relation to the metering diaphragm 206 in assembled relation with the carburetor body and the member 62.

Both the metering diaphragm 206 and the gasket 212 are respectively fashioned with a plurality of openings 216 and 218 which, in assembly, are in registration to accommodate the securing bolts 68, shown in FIGURES 4 and 8, the bolts retain the gasket and diaphragm in assembled operative relation. The metering diaphragm 206 and the gasket 212 are formed respectively with openings 220 and 222 which register in assembly with the fuel passage 178, shown in FIGURE 5, to facilitate fuel flow to the region of the inlet valve 88 in the carburetor. The metering diaphragm 206, utilized in lieu of the diaphragm 56, is influenced by aspiration in the mixing passage to control the fuel inlet valve 88 through the medium of the lever 74 in the manner hereinbefore described.

The inlet and outlet flap valves associated with the pumping component, whether the valves are integral with the metering diaphragm, as shown in FIGURE 4, or formed in a separate member at an edge region of the metering diaphragm as in FIGURE 12, or fashioned as integral components of a gasket 212 adjacent the metering diaphragm 206, perform their function of controlling liquid fuel flow to the region of the fuel inlet valve 88 of the carburetor by pumping pulsations establishing pumping action by distortion or flexing of the pumping element124.

In all forms, the flap valves are adjacent or substantially in the plane of the metering diaphragm whereby a compact fuel feed system and carburetor is provided.

FIGURES 15 through 17 illustrate a carburetor embodying a modified arrangement of pulse responsive fuel pump construction. FIGURE 15 is a view similar to FIGURE 2 and includes a carburetor body or member 1041 to which is secured a member 62a and a closure member 144a of the same construction as the corresponding elements shown in the form of the invention in FIG- URES 1 through 4-. The carburetor body 10a is equipped with a metering diaphragm, 56a, and the mechanism actuated by the diaphragm for controlling fuel flow into the carburetor fuel compartment and the fuel channels for conveying fuel into the mixing passage 12a are of the same construction as shown in FIGURES 3 and 8.

The body 10a is fashioned with a bore or recess 230 providing a chamber in which is disposed a pumping component 232 of flexible or yieldable material of the same general character as the pumping component 124 shown in FIGURE 6. The axis of the bore 230 and the elongated axis of the pumping component 232 are normal to the plane of the diaphragm 56a. The pumping component 232 is of fluted shape and cross section as in the form shown in FIGURE 6. The region of the body 10a at the entrance of the bore 230 is provided with a counter bore to accommodate the flange 234 formed at the entrance end of the flexible pumping component 232.

The chamber provided by the recess 230 in the body I 10a is the pulsing or pumping chamber and the interior chamber 236 of the flexible component 232 is the fuel chamber. The engine mounting flange 22a of the car- 'buretor body is provided with a pulse channel 238 extending through the mounting flange which is in registra tion with an opening in the engine crankcase, such as the opening 27 shown in FIGURE 1, the pulse channel 238 opening into the bore or chamber 230.

Thus, varying fluid pressures in the crankcase of the engine are transmitted through the pulse channel 238 to the chamber 230 and cause flexing of the pumping component 232 to establish a pumping action of the fuel chamber 236 provided interiorly of the pumping component. The fuel channels and the ports associated with It) the pumping component are illustrated in FIGURES 16 and 17. The diaphragm 56a is fashioned with an integral inlet flap valve 242 which cooperates with an inlet port 244 in the member 62a. The diaphragm is fashioned with a second or outlet flap valve 246 integral with the diaphragm and which controls a fuel outlet port 248.

Spaces are provided in the body 10a (as shown in FIG- URE 16) to accommodate the opening movements of the flap valves 242 and 246. The space above the inlet valve 242 is in communication with the outlet port 248 by connecting fuel passages or channels 250 and 252.

The interior of the pumping component 232 is in communication with the fuel channel 252 by means of a passage or duct 254, the gasket 58a and the diaphragm 56a having registering openings in communication with the passage 254 to admit fuel into the chamber 236 in teriorly of the pumping component 232.

The space above the outlet flap valve 246 is in communication with connecting passages or channels 176a and 173a arranged to convey fuel to the region of the carburetor inlet control valve 88 shown in FIGURE 8. A seal is effected at the region of the flange 234 by the gasket 58a and the diaphragm 56a disposed between the flange and the contiguous region of the plate member 62a.

It will be apparent from the foregoing description that in this form of the invention the varying fluid pressures or pulses in the crankcase are communicated to the chamber 230 in the carburetor body through the pulse channel 238 to effect alternate expansion and contraction of the fluted wall regions of the flexible pumping component 232. The alternate expansion and contraction of the pumping component 232 varies the volume of the interior chamber 236 provided by the pumping component to effect a pumping action which influences the inlet and outlet valves 242 and 246 to alternately open and close the fuel ports to effectively pump liquid fuel from a supply through the inlet port 244 and channels or passages 250, 252, 248, 176a and 178a to deliver fuel to the region of the inlet valve in the carburetor.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. A fuel feed system for an internal combustion engine including, in combination, a first member having a fuel and air mixing passage and an unvented fuel compartment, a throttle valve in the mixing passage, a fuel inlet duct for said fuel compartment, valve means for said duct, passage means in communication with the fuel compartment for conveying fuel into the mixing passage, means including a diaphragm influenced by aspiration in the mixing passage operable during delivery of fuel from the fuel compartment into the mixing passage for controling said valve means to regulate fuel flow into the fuel compartment, a cavity in the first member providing a first chamber, a tubular sac-like element of flexible material in said cavity having parallely arranged fluted regions providing a second chamber, a second member secured to the first member, a body of flexible material disposed between said first and second members, inlet and outlet flap valves integrally formed on said body, fuel inlet and outlet ports controlled by said flap valves, the inlet port being adapted to be connected with a supply of liquid fuel, passage means establishing communication with one of said chambers and the fuel inlet duct in the first member, the other of the chambers being in communication with a source of varying fluid for flexing the tubular element to pump fuel from the supply to the region of the fuel inlet duct in the first member.

2. A fuel feed system as in claim 1, and wherein said diaphragm and said body of flexible material are integral.

3. A fuel feed system as in claim 1, and wherein said 1 1 1 2 diaphragm and said body of flexible material are separate 3,090,608 5/ 1963 Phillips. stacked members. 3,160,681 12/1964 Johnson.

FOREIGN PATENTS References Cited by the Examiner 636,902 12/1963 Belgium.

UNITED STATES PATENTS 5 2,677,393 5/1943 Cornelius 103148 X 2,979,312 4/1961 Phillips. RONALD R. WEAVER, Examiner.

HARRY B. THORNTON, Primary Examiner. 

1. A FUEL FEED SYSTEM FOR AN INTERNAL COMBUSTION ENGINE INCLUDING, IN COMBINATION, A FIRST MEMBER HAVING A FUEL AND AIR MIXING PASSAGE AND AN UNVENTED FUEL COMPARTMENT, A THROTTLE VALVE IN THE MIXING PASSAGE, A FUEL INLET DUCT FOR SAID FUEL COMPARTMENT, VALVE MEANS FOR SAID DUCT, PASSAGE MEANS IN COMMUNICATION WITH THE FUEL COMPARTMENT FOR CONVEYING FUEL INTO THE MIXING PASSAGE, MEANS INCLUDING A DIAPHRAGM INFLUENCED BY ASPIRATION IN THE MIXING PASSAGE OPERABLE DURING DELIVERY OF FUEL FROM THE FUEL COMPARTMENT INTO THE MIXING PASSAGE FOR CONTROLING SAID VALVE MEANS TO REGULATE FUEL FLOW INTO THE FUEL COMPARTMENT, A CAVITY IN THE FIRST MEMBER PROVIDING A FIRST CHAMBER, A TUBULAR SAC-LIKE ELEMENT OF FLEXIBLE MATERIAL IN SAID CAVITY HAVING PARALLELY ARRANGED FLUTED REGIONS PROVIDING A SECOND CHAMBER, A SECOND MEMBER SECURED TO THE FIRST MEMBER, A BODY OF FLEXIBLE MATERIAL DISPOSED BETWEEN SAID FIRST AND SECOND MEMBERS, INLET AND OUTLET FLAP VALVES INTEGRALLY FORMED ON SAID BODY, FUEL INLET AND OUTLET PORTS CONTROLLED BY SAID FLAP VALVES, THE INLET PORT BEING ADAPTED TO BE CONNECTED WITH A SUPPLY OF LIQUID FUEL, PASSAGE MEANS ESTABLISHING COMMUNICATION WITH ONE OF SAID CHAMBERS AND THE FUEL INLET DUCT IN THE FIRST MEMBER, THE OTHER OF THE CHAMBERS BEING IN COMMUNICATION WITH A SOURCE OF VARYING FLUID FOR FLEXING THE TUBULAR ELEMENT TO PUMP FUEL FROM THE SUPPLY TO THE REGION OF THE FUEL INLET DUCT IN THE FIRST MEMBER. 